Switch interlock mechanism



May 24, 1966 w. 1 TANCRED 3,253,090

SWITCH INTERLOCK MECHANISM Filed Oct. 14, 1963 2 Shees--SheefI l fg INVENTOR.

mum/y L TANQRED ATTQRNQY May 24, 1966 w. 1 TANCRED 3,253,090

SWITCH INTERLOCK MECHANISM INVENTOR. Www AM L .Tamcaeb ATToRNY United States Patent O "a 3,253,090 SWITCH INTERLOCK MECHANISM William L. Tancred, West Los Angeles, Calif., assignor to Controls Company of America, Melrose Park, Ill., a corporation of Delaware Filed Oct. 14, 1963, Ser. No. 315,926 Claims. (Cl. 200--5) switch assembly should be tease-proof, i.e., after a switch has been actuated it should be impossible for another switch station to be moved toward a switch actuated position a sufficient amount to release the prior actuated switch without moving suiciently to set itself. Interlock mechanisms have been proposed for multiple station switch assemblies to achieve su-ch operation; however, they generally have been of relatively complex design, such as utilizing a number of relatively movable parts to transmit motion between separate switch stations, e.g. actuation of one switch station releasing any prior actuated switch station. Such designs are generally costly, diiiicult t-o assemble and susceptilble to tolerance build-up in the component parts such that it becomes difiicult to maintain consistent operating characteristics, such as teaseproof operation, without unduly increasing the cost of lfabrication and/or assembly.

An object of the invention is to provide an interlock mechanism for use in a multiple switch station assembly, which interlock mechanism is of relatively simple and economical construction and which `facilitates assembly.

A further object of the invention is to minimize tolerance build-up and the problems resulting therefrom in an interlock mechanism for use in a multiple switch station assembly.

It is also desirable in various multiple switch installations that one and only one switch station be capable of actuation at a given time and another object of this inventionv is to provide a relatively simplified and economical mechanism which is icapable of preventing simultaneous actuation of two or more switch stations.

For the achievement of these and other objects, this invention proposes to provide an interlock member which is essentially of unitary construction and is free of relatively moving parts. The interlock member is mounted in the multiple switch station for movement in response to actuation of the various switch stations such that it is moved, by actuation of one switch station, into a position for engagement by any one of the remaining unactuated switch stations rwhen the latter are subsequently actuated. The interlock member being arranged such that subsequent actuation of a switch station results in movement of the interlock member to release the prior actuated switch station.

Other objects and advantages will be pointed out in, or be apparent from, the speciiication and claims, as will obvious modications of the embodiment shown in the drawings, in which:

|FIG. 1 is a side elevation of a multiple station switch assembly constructed in accordance with this invention;

FIG. 2 is a section view taken generally along line 2-2 of FIG. 1;

3,253,690 Patented May 24, 1966 ICC FIG. 3 is a section view taken generally along line 3-3 of FIG. 2;

lFIG. 4 is a perspective view of the rocker plate; and

FIG. 5 is lan enlarged view of the interlock member and a pair of the plunger forks illustrating the relative positions of the interlock member and forks midway between their actuated and unactuated positions.

With particular reference to the drawings, a multiple station switch assembly is illustrated as including switch stations 10, 12, 14 and 16 and a frame `18 comprising top plate 20, base 22, end plates 24 and 26 and vertical plate 28. The switch stations include operating plungers 30, 32, 34 and 36 suitably mounted in frame 18 for sliding movement. Switch means 38 is provided at each of the stations but for clarity of description and convenience switch means has lbeen illustrated at only one of the stations and it will be appreciated that the switch means is identical at each of the stations. In this instance, the switch means comprise a pair of switches 40 and 42 supported in bracket 44. The bracket is formed by a pair of legs 46 and -48 each including tang portions 50 and 52 which dit into suitable openings in base 22 of the frame. I egs 46, `48 are connected by a web 54 which projects to top plate 20 for connection to the frame by suitable fastening means 58. It will be appreciated that the number of switches at each station can be varied as desired. Where a pair of switches are used, each plunger is provided with a pair of projections 60 and 62 arranged to engage switch buttons 64 and 66 for actuation of the switches -as the plungers are depressed.

As illustrated in the drawings, plungers 30, 32 and 34 are shown in their normal or unactuated positions so that their respective switch means are in an unactuated state and plunger 36 is illustrated in its actuated position wherein its switch means is invan actuated state. Each of the switch stations is also provided with toggle means 68, 70, 72 and 74 which are effective to selectively bias and insure movement of the operators toward their actuated and unactuated positions. The toggle mechanisms a-t the switch stations are identical and accordingly only that at station 16 will be described in detail. Structurally, toggle mechanism 74 comprises a pair of compression springs 76 and 78 seated between formed ledges 80 and 82 extending from vertical pla-te 28 of the frame and a ledge 84 xed 4to and movable with operator plunger 36. With this arrangement, com-pression springs 76 and 78 provide an over-center mechanism which will insure movement yof the operator plunger to either of its two extreme positions after it has gone over center and will hold the operator plungers in either their unactuated or actuated positions.

An elongated interlock rocker member 86 is supported between fra-me end walls 24 and 26 with its longitudinal axis extending parallel to the direction of alignment for the plungers so that the rocker member is positioned in the path of the operator plungers 30, 32, 34 and 36 as they move toward their actuated positions. structurally, the interlock member comprises a rocker plate 88 formed to include a central depression 90 extending the length of the plate and having rolled edges 92 and 94 extending along the opposed sides of the plate. A shaft 96 is suitably xed to the plate 88 in depression 90, for example by welding, and is journaled in bushings 98 and 100 carried on end walls 24 and 26 so that the shaft denes the pivotal axis for rocker member 86.

Rocker engaging forks 102, 104, 106 land 108 are supported on the plungers by pins 110, 112, 114 and 116 extending between pairs of projections 60 and 62 of each of the operating plungers. The forks are movable with the operating plungers and, furthermore, are capable of. pivotal movement on their respective pin mountings.

v the forks and rocker plate during operation.

Structurally the free end of each of the fork members include rel-atively spaced depending arms 118 and 120. The terminal ends of each of the arms 118 and 120 are also generally bifurcated to provide sea-ts 122 and 124 for engagement with the rocker plate. Elongated rods 126 .and 128 are received in the rolled edges 92 and 94 of the vrocker plate and the plate is also provided with pairs of oppositely directed notches 129, 131 opening into opposed edges 92 and 94. The pairs of notches are relatively spaced along the longitudinal axis of lthe rocker plate and the notches `are aligned with forks 102-108 to permit engagement of the forks with lthe rods 126 and 128 and also to provide clearance for relative movement between the forks and rocker member as will be more clearly described in connection with a discussion of the operation of the switch assembly.

In operation, as operating plunger 36 was depressed, portion 120 of fork 108 will have engaged rod 128 of the rocker member and movement of the operating plunger to its actuated position will have pivoted the interlock rocker member clockwise about its axis. It will be noted that when the operating plunger goes past the overcenter position of toggle 74, the toggle will insure movement of the plunger to its actuated position and thereafter will provide a force tending to hold the plunger in its actuated position. Thus the condition illustrated in FIG. l will obtain, the switch mechanism at station 16 will be actuated, operating plunger 36 willl be held in its actuated lposition and the rocker member will be positioned with `is posi-tioned for engagement with seat 122 of either fork Now should one of the stations 10, 12 or 14 be moved toward its actuated position, to select -another operational cycle or continue a sequence of operations, the prior actuated station 16 will be released and returned to its unactuated position. M-ore particularly, if one of operating .plungers 30, 32 or 34 is moved toward its actuated position, the seat 122 of its forks will engage rod 126 so that the rocker member will be pivoted counterclockwise as the plunger moves toward its actuated position. This pivotal movement of the rocker member will, through the engagement of rod 128 in seat 124 of fork 108, raise and move plunger 36 toward its unactuated position. With reference to FIG. 5, it will be noted that during this movement the forks 108 and 106, assuming station 14 to be the subsequently actuated, will pivot about their pin connection on the plungers so that the free or unengaged end of each fork will pass through respective ones of the notches in the rocker plate to provide clearance between The condition of FIG. 5 illustrates the forks midway between normal and actuated positions. Therefore, actuation of one switch station will insure the release of any prior actuated switch station. Furthermore, it will be appreciated that the toggles 68-78 yalso insure movement of the operating plungers to and holding of the plungers in their unactuated position.

With the construction just discussed, the switch interlock device is essentially a unitary member incorporating no relatively moving parts. Hence tolerance build-up problems are kept to a minimum as yare fabrication and assembly costs. Furthermore, this construction lends itself particularly well to providing a tease-proof type of operation in that the switch operating elements and the toggles can be arranged such that before the toggle of a prior actuated switch station will be moved over center toward its normal unactuated position, the toggle of a subsequently actuated switch will have to be moved over center toward its actuated position. The tease-proof characteristic can be more accurately held since the problem of tolerance build-up in the interlock device is minimized.

In switch interlock mechanisms of this type it is also common practice to provide a construction wherein simul- -gates at any one time.

taneous actuation of more than one of the switch st-ations is prevented. A number of devices have been proposed for achieving this end and this invention contemplates a relatively simplied arrangement for preventing such simultaneous actuation. More particularly, the 'vertical plate 28 of the frame is provided with cut-out notches 130, 132 and 134 positioned one between each pair of adjacent operating plungers or stations. Each notch has a gener-ally V-shaped upwardly facing portion 136, 138 and 140. Gates 142, 144 and 146 are mounted in the notches and include turned ends 148, and 152 arranged for engagement with portions 136, 138 and 140 to thereby complete a relatively simplied pivotal support for the gates. Structurally, the gates take the form of an inverted T each Vincluding an elongated stem 154 and laterally projecting arms 156 and 158 extending from either side of the stem. A tab 160 on each gate extends into a `suitable opening 161, 162 and 163 in the base of the frame. Projections 164, 166, 168 and 170 are provided on and 'movable with each of the plungers 30-36 and are arranged for engagement between respective pairs of the gates. The gates are so arranged that only one of such projections 164-170, can be received between the Thus, with operating plunger 36 depressed, its projection 170 engages gate 146 and pivots all of the gates about their support points closing the gates on each other and blocking passage of any of the other projections between the gates. Thus simultaneous depression of the operating plungers 30, 32, 34 and 36 is prevented. Obviously, when the switch stations are sequentially operated the prior actuated plunger 36 is released by the interlock member 86 and moved out of engagement with the gates allowing the projection of the subsequently depressed plunger to move into the gates and permit the plunger to assume its actuated position.

Although this invention has been illustrated and described in connection with a particular embodiment thereof, it will be apparent to those skilled in the art th-at various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What I claim is: 1. A multiple station switch assembly comprising, in combination, a plurality of switch means, lan operating member for each of said switch means and each mounted for movement relative to said switch means between an actuated and `an unactuated position, an elongated interlock member, v ymeans supporting said interlock member in the path of movement of said operating members and for pivotal movement about a longi-tudinal axis and with portions of said interlock member extending on opposite sides of said axis, and interlock engaging me-ans on each of said operating members straddling said `axis and positioned for selective engagement with one of said po-rtions of said interlock member on one side of said axis, sai-d interlock engaging means arranged so that when one of said operating members is moved toward its actuated position a portion of said interlock member on one side of said axis is engaged by and moved with said one operating member to pivot said interlock member about its laxis to position the portions -of said interlock member on lthe opposite side of said axis for engagement with the interlock engaging means of the remaining operating members which are in said unactuated position, sub-sequent actuation of one of said unactuated operating members pivoting said interlock member to move said one operating member from said actuated to said unactuated position. 2. The multiple station switch `assembly of claim 1 including toggle means connected to each of said operating 3. A multiple station switch assembly comprising, in

combination,

a plurality of switch means,

.an operating member for each of s-ai-d switch means mounted for movement relative to said switch means between an actuated and an unactuated position,

lan elongated interlock member,

means supporting said interlock member in the path of movement of said operating members for pivotal movement about a longitudinal axis and with portions of said interlock member disposed on opposite sides of and spaced radially outwardly from said axis,

.and operating means on each of said operating members for movement therewith and for selective engagement with the portions of said interlock member, each of said operating means including first and second portions relatively spaced transversely of said axis with the distance between said rst and second portions being different from the distance between the portions of said interlock member on opposite sides of said axis and said rst and second portions being arranged for selective engagement with the portions of said interlock member on opposite sides of said axis, said interlock member and said operating members arranged so that Iupon actuation of one operating member said one operating member engages and moves said interlock member to engage 4and transmit movement of said interlock member to `and move a prior actuated operating member to its unactuated position.-

4. A multiple station switch assembly comprising, in

combination,

a plurality of switch means,

an operating member for each of said switch means mounted for movement relative to said switch means between an actuated and unactuated position, sai-d operating members being positioned in relative alignment,

Ian elongated interlock member,

means supporting said interlock member in the path of movement of said operating members with its longitudinal axis extending generally parallel to the direction of alignment of said oper-ating members and for pivotal movement about a longitudinal axis,

said interlock member including portions disposed on opposite sides of and spaced radially outwardly of said pivotal axis,

and a fork-like member supported on each of said operating members for movement therewith land relative thereto and including ar-m portions extending toward and arranged to straddle said pivotal axis, said arrn portions of each fork-like member being spaced .apart a distance different from the distance between said interlock member portions on opposed sides of said pivotal axis and arranged for selective engagement with said interlock member portions so that upon movement of one of said Ioperating members toward an actuated position one of said arm po-rtions engages said interlock member to pivot said interlock member about said pivotal axis with the interlock `member por-tions on the opposite side of said pivotal axis being moved to a position for eng-agement with 4an arm portion of the fork-like member of said operating members in said unactuated position so that ymovement of another of said operating members to said actuated position pivots the prior actuated operating member to its unactuated position.

S. The multiple stati-on switch assembly of claim 4 wherein said interlock member includes,

la plurality of relatively spaced portions extending on opposite sides of said pivotal 'axis to deiine a plurality of open notches therebetween,

means extending between adjacent ones of said portions Iand spaced outwardly of said pivotal axis,

and wherein the arm portions of said fork-like members are .aligned with respective ones of said notches for selective engagement with the means supported therein, the dist-ance between said arm portions being less than the distance between said last named means.

6. The combination of claim 4 wherein said portions of said interlock member .are arranged in aligned pairs on opposite sides of said pivotal axis and wherein said interlock member includes openings adjacent each of said interlock member portions to receive and provide clearance between said interlock member portions and said fork-like members upon movement of said operating members relative to said interlock member.

7. The multiple station switch assembly of claim 4 including,

a frame,

a gate member disposed intermediate adjacent pairs of said operating members and extending into the path of movement of said operating members,

one of said frame and gate members including a cutout portion and the other including a lateral projection extend-ing into said cut-out portion to define a pivot connection for each of sai-d gate members,

and means on each of said operating members arranged Ifor engagement with said gate members to pivot said gate members to a closed position as one of said operating members is moved to its actuated position, said gate members relatively arranged to per-mit only one of said operating members to assume an actuated position at any one time.

S. A-c-tuating means for a switch assembly including a plurality of switch means and comprising, in combination,

an operating member for each of said switch means mounted for movement relative to said switch means between lan actuated and an unactuated position, said operating members being arranged in relative alignment,

an elongated interlock member,

means supporting said interlock member for pivotal movement about a longitudinal axis `disposed intermediate the opposite longitudinal edges thereof and in the path of movement of said operating member,

said interlock member having a body portion including radially extending portions on opposite sides of said axis and relatively spaced along said ,axis to deiine openings therebetween,

means supported in the openings between said radial portions,

and a fork-like 'member on each of said opera-ting members for movement therewith and relative thereto, said fork-like members including arm portions extending toward and straddling said axis for selective engagement with said means in said openings, the distance between said arm portions of each fork-like member being less than t-he `distance between the means in said openings on opposite sides of said `axis.

9. A multiple station switch assembly comprising, in

combination,

a plurality of switch means,

operating means for each Iof said switch means,

' means mounting said operating means in general relative alignment and for movement relative to said switch means 'between an actuated and an unactuated position,

said operating -means each including a pair of iirst release means spaced apart in a direction transverse to a direction of alignment of said switch means,

Aan interlock member having an axis extending generally in the direction of alignment of said switch means and including second release means lcorresponding to each of said iirst release means and said second release means fo-r each of said operating means being relatively spaced apart in a direction ltransverse to said axis, e and support means supporting said interlock member in the path of movement yof said operating means and for engagement -With and movement by said operrating means, said support means als-o supporting said interlock member vfor engagement of said second release lmeans with said fir-st rele-ase means and sfo that movement of said interlock member in response to movement of one of said operating means toward an actuating position is 4transmitted to a prior actuated operating means to move said prior actuated operating means to its unactuated position. 10. The multiple station switch assembly of Iclaim 9 wherein said support means supports said` interlock mem- 8 ber for pivotal movement in response to movement of said operating means and wherein the release means of each of said pair of rrst release means and the corresponding second release means are positioned on opposite sides of lthe pivotal axis of said interlock member.

References Cited bythe Examiner UNITED STATES PATENTS 2,802,915 8/1957 Hutt ZOO-5 X 3,125,895- 3/1964 tRorss 200-5 X l 3,183,315 5/196'5 Kiely 200-5 KATHLEEN H. CLABFY, Primary Examinar.

M. GINSBURG, Assistant Examiner. 

9. A MULTIPLE STATION SWITCH ASSEMBLY COMPRISING, IN COMBINATION, A PLURALITY OF SWITCH MEANS, OPERATING MEANS FOR EACH OF SAID SWITCH MEANS, MEANS MOUNTING SAID OPERATING MEANS IN GENERAL RELATIVE ALIGNMENT AND FOR MOVEMENT RELATIVE TO SAID SWITCH MEANS BETWEEN AN ACTUATED AND AN ACTUATED POSITION, SAID OPERATING MEANS EACH INCLUDING A PAIR OF FIRST RELEASE MEANS SPACED APART IN A DIRECTION TRANSVERSE TO A DIRECTION OF ALIGNMENT OF SAID SWITCH MEANS, AN INTERLOCK MEMBER HAVING AN AXIS EXTENDING GENERALLY IN THE DIRECTION OF ALIGNMENT OF SAID SWITCH MEANS AND INCLUDING SECOND RELEASE MEANS CORRESPONDING TO EACH OF SAID FIRST RELEASE MEANS AND SAID SECOND RELEASE MEANS FOR EACH OF SAID OPERATING MEANS BEING RELATIVELY SPACED APART IN A DIRECTION TRANSVERSE TO SAID AXIS, AND SUPPORT MEANS SUPPORTING SAID INTERLOCK MEMBER IN THE PATH OF MOVEMENT OF SAID OPERATING MEANS AND FOR ENGAGEMENT WITH AND MOVEMENT BY SAID OPERATING MEANS, SAID SUPPORT MEANS ALSO SUPPORTING SAID INTERLOCK MEMBER FOR ENGAGEMENT OF SAID SECOND RELEASE MEANS WITH SAID FIRST RELEASE MEANS AND SO THAT MOVEMENT OF SAID INTERLOCK MEMBER IN RESPONSE TO MOVEMENT OF ONE OF SAID OPERATING MEANS TOWARD AN ACTUATING POSITION IS TRANSMITTED TO A PRIOR ACTUATED OPERATING MEANS TO MOVE SAID PRIOR ACTUATED OPERATING MEANS TO ITS UNACTUATED POSITION. 